Charge pumps may be generally used to boost (e.g., double) a direct current (DC) voltage at an input to a higher DC voltage at an output. A charge pump may accomplish this voltage boost by alternatively configuring a capacitor between an input and a low clock signal for receiving energy and configuring the capacitor between a high clock signal and an output for providing energy. The charge pump may include two symmetric portions that operate in complementary fashion. In particular, while a first portion is receiving energy (i.e., charging) a second portion is providing energy (i.e., discharging) and vice versa. In this way, the combined result at the output is a DC voltage that is higher than the input, and any noise from switching (e.g., spikes) may be suppressed by a capacitor at the output.
The switching in charge pumps may be accomplished using diodes, but as voltages decrease these devices have increasingly poor power conversion efficiency (i.e., efficiency) because the voltage drops across the diodes become increasingly comparable to the input voltage of the charge pump. Additionally, in some charge pump circuit topologies, the efficiency of the charge pump suffers from current crosstalk during switching. Accordingly, new charge pump circuits are needed to provide efficient operation, especially in a low voltage regime.